Supervisory signaling system.



w. e. BLAUVELT. SUPEBYISORY SIGNALING SYSTEM. APPLIOATION FILED OUT. 28,1910.

Patented Apr. 25, 1911.

UNITED STATES PATENT orrron.

WILLIAM G. BLAUVELT, 'OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN TELEPHONEAND TELEGRAPH COMPANY, A CORPORATION OF 'NEW YORK.

SUPERVISORY- SIGNALING SYSTEM.

Specification of Letters Patent.

990,21 Application filed October 26, 1910. Serial No. 589,207.

To all whom it may concern: I

Be it known that I, VVnmmrrG. BLAU- yin/r, residing at New York, boroughof Manhattan, in the county of New York and State of New York. haveinvented certain Improvements in Su'lmrvisory Signaling Systems, ofwhich the following is a spccifi? cation.

This invention directed to the signals em .)l(')ycd for supervisingtelephone calls. Ordinarily in manual systems, the cord circuit by whichthe lines are united at the central station has in both the answeringand calling ends a single signal device, as an incandescent lamp, whichis caused to glow when the receiver of the corresponding substation isupon its hook, and to be extinguished when said receiver is removed.This gives the operator an indication of the conditions at thesubstations, which is in many instances su'llicient, but in othersputs'upon her an undue burden in noting and rcl'nemboring the times ofappearance and disappearance of the signals. For example, the zallingsubscriber after the completion of a particular conversation, or becausethere was an *ror in the connection, will keep the receiver off theswitchhook when he desires to speak with the operator. Unless the latterobserved. the lighting and extinguishing of the called supervisory lamp,this leads herto again ring over the called line, or to wait for thecalled subscriber to answer. Drag upon the operators work, and delay andannoyance of the subscriber results. A further difficulty arises fromthe fact that in measured service the operator has no direct means ofknowing when the calls have reached a stage at which they should becharged, unless, as before pointed out, she hasseen the changes in thecalled line supervisory.

The present invention provides plural signals for theca'lled line, bywhich, for each connection, separate indications are given when thesubscriber responds to the ring of the bell and when he terminates theconversation.

In the accompanying diagrammatic drawing my invention is illustrated inconnection with a manual cord circuit, though it is to be understoodthat it is applicable to all systems where similar su )crvision isuseful.

The letters A and B esignate telephone substations, the lines a and b ofwhich unite them to jacks J and J respectively, at a central station C.At the central station are circuits for connecting the lines, in thepresent instance an operators cord circuit 0 being shown, this having ananswering plug I and a. calling 'plug P These -appear adjacent to thejacks J and J and therefore A may be consideredas the calling and B asthe called substation. In every rcspect,savc as it relates tosupervision of the called line, the cord circuit 0 may be as usual, andonly the novel portions will be particularly described.

Associated with, the cord circuit is an automatie switching mechanismD,the arrange. ment and functions of which will depend upon thecharacter of the system of which it is a part, but which, in any event,is adapted to assume successive controlling positions in regularsequence. In the present instance, it is employed solely as ameans forgoverning the supervisory signals of the called subscriber, and for thispurpose'it consists of a shaft cZ upon which is fixed a series of\ camsc, the peripheries of which cooperate with springs f to force themagainst or permit them to separate from contacts 9. These cams, springsand contacts all appear in two places (in the drawing, in dotted linesin their actual relation to the shaft d and in full lines at points mostclearly developing the circuit organization. In the latter case, theyare distinguished from one another by numerals affixed to theirreference letters. The switch shaft with its cams may be moved fromposition to position by a motor magnet m actuating ratchet mechanism. Apulsator 22 supplies intermittent. currentfrom battery B throughconductor 10 to the motor magnet m, and thus rotates the shaft wheneverits circuit is completed at one of the contacts of the sequence switchI) to ground or other return conductor. This ground connection may be atsome external point or local to the switching mechanism itself, the camc controlling the latter condition and determining the correct stoppingpoints of the switch shaft. lVhen the spring f cooperating with this camis separated from the contact g, this being in the positions indicatedby the numerals placed at the opposite side of the spring from thecontact, the projection 11 upon said spring lies in a depressiorrlQ inthe periphery of the cam, and the shaft with e are included in theconductor '10 of the now resting upon contact" there is a, local theassociated cams is properly positioned. Upon the completion of thecircuit of the motor magnet in at some point in the system theprojection rides out of the depression, and when resting upon elevationsof the cam e closes local circuit for the motor magnet which insuresrotation of the shaft to the next position at which the cams are tostop, regardless of external conditions. The numerals applied to thecontacts of the remaining cams show the positions in which said contactsare closed. ()f the other cams, c has its spring f normally resting upona contact r which is joined to the front contact 13 of a relay R in thethird conductor L of the cord between the central station battery andthe sleeve contact of the calling plug P I The normal contact 13 ofrelay R is joined to the contact 9 of cam 6 The spring f of this cam andcontact 9' of cam motor magnet. From spring f of earn a a conductor 14leads to the front contact 15 of the called line supervisory relay ltsitu-' ated in the cord conductor L and energized only when the receiverat the substation is off its switchhook. The alternate contact g isunited by a conductor 10 through a resistance 17 with parallel branches18 and 19, in which are a ringing signal 0 and a disconnecting signal 0respectively, both of these preferably being incandescent lamps.Resistances 20 and 21am interposed bet ween the conductor 16 and thelamp 0, and the juncture of these resistances is connected to battery.The conductors 18 and 19 tenni nate, respectively, iircontaets g and gof cam 6 the spring f of which is joined to ground. As thus describedillustrated both signal lamps O and. 0 may be said to be directlyassociated with one and the same :ord circuit, C, and particularly withthe calling end of said cord circuit, and both positioned and adapted tosignal one and the same central station operator.

The operator, having received a call for substation I3 and found itsline Z) not in use, inserts the plug l of'thc cord circuit. with whichshe has answered into the jack J? This causes the energization of relaylt in circuit with the cutoll' relay of the called line. The closure ofcontact 13, together with normal contact of the sequence switch, gives aground for comluctor 10, and impulses ot currentarc applied by the pulsator [i to the motor magnet of the switclnwhich is driven to its secondposition. Ground'c't oring 7"- circuit for the lamp tl'irough'conductorl8 and re, d l, lighting thislamp and thus preparing it to indicate thesuhscriheus response the ringing of his bell. The signalhii thereforebeen remlered cllectivc by the a sd'ciation of the' jack and plum' Thesubsequent taking down of the receiver energizes supervisory relay Rand. gives a. circuit through its front contact 15, conduct r 14, spring7, contact g" and conductor 10 for the motor magnet. The switch Dthereupon takes its third position, opening contactgq and thusextinguishing the lamp 0 to inform the operator that the calledsubscriber has answered. Upon its alternate contact 9*" the spring fcloses the local circuit 15.) for the disconnecting lamp 0 but this isshunted by a circuit from battery to ground through resistance 17,conductor 16, switch contact 5 conductor 14: and contact 15of relay R Itdoes not receive sutlicient current to cause it to glow, but has beenprepared t'or signaling by the removal of the receiver. \V hen, however,the. called subscriber hangs up the receiver, the armature of relay Rfalls otl', breaking the shunt circuit and lamp 0 lights. This gives tothe operator positive knowledge that there has been connnunicationbetween the calling and called substations, and that, if the supervisorylamp of the calling line also lights, she may withdraw the plug P and,in measured service, record the call. If the calling line supervisoryremains out, it at once indicates to the operator, withouteffort torecall previous conditions, that she should again connect her set withthe cord to inquire what is desired. When the operator pulled out thecalling plug, the relay R, be ing'rcleased, completed at its backcontact 13 a circuit for the motor magnet by way of switch contact g andconductor 10. The switch I) advanced to its normal position and wasstopped by the opening of the contact H the called subscriber had failedto answer, the san'lc circuit would have resulted upon thedeiincrgization of relay R in the second position, and contact 9 wouldstill be closed in the third position, causing the completerestorationof the switch.

Having thus described my invention, I claim: 7

I. la a telephone system, a central station and a substation, aplurality. of supervisory signal devices at the central station, allposilioncd and adapted to signal one and the same. central stationoperator and means for successively bringing said signal devices un derthe control of the substation.

2. in a tclc 'ihone system, a central station and a substation, aplurality of signal devices at the central station, all positioned andadaptedto signal one and the same central station operator aud automaticmechanism at the central station for successively bringing said signaldevices under the control of the sul'istation.

5). in a telephone system, a central station and :1 substation, two'supcrvisoty signals, both positioned and adapted to signal, one and thesame central station operator and means controllable-by'central stationapparatus for rendering one signal effective and by substation apparatusfor rendering the other signal effective. i

4. Ina telephone system, a central station and a called substation, andtwo supervisory rality of signal devices associated with the ing circuitandboth controllable from one'of 30. two telephone-lines when suchlinesare cinsignals both positioned and adapted to sig-v iial one andthe same central station operator and controllable by thesubstationapparatus at different stages of a call.

5. The combination with telephone lines, of a connecting circuittherefor, and a plu connecting circuit, all of said signal devices beingpositioned and adapted to signal one and the same operator andcontrollable during a single connection by the condition of one of thesubstation lines.'

' 6. The combination with telephone lines of a connecting circuittherefor, anda lurality of supervisory signal devices directlyassociated with the calling end of the con- 'necting circuit andcontrolled by a called telephone line.

7. The combination with telepho e lines, of a connecting circuittherefor, a-no a. ring ing supervisory signal and a disconnecting signaldirectly associated with the connectnected by the connecting circuit;

" 8. -'lhe'combination witha telephone substation apparatus, of a cuitincludin plurality of signal .d'evices, switching means for activelyassociating. one and then an other of the signal devices-with thecircuit,

, substation apparatus and means controlled by the condition of the foractuating the switching means. i i

9. The 'combination'with. telephone lines and a connecting circuit, of-'a sequence switch providedwith a. plurality of contacts, called linesupervisory. signals connected with said contacts and effective indifferent positions of the sequence switch, and means for actuating thesequence Switch to said different positions.

10. Telephone lines, a connecting circuit therefor, a relay associatedwith the connect jing circuit, switching mechanism provided with motorIneans and With a plurality of contacts, said motor means beingcontrolled by the relay, and called line supervisory sig- "nals joinedto different contacts of the switching mechanism. 11..Telephone l1nes, aconnecting circuit therefor, switching mechanism associated with theconnecting circuit and having a plurality ofcontacts a ringing signalconnected to one contact of the switching mechanism, a disconnectingsignal connected to another contact thereof, means controlled by unitingthe connecting circuit with a called line for closing the contact to.theringing signal, and means operating upon .the response of the calleds'ubscriberfor closing the contact to the disconnecting signal.

12. Telephone lines, a. connecting circuit therefor, switching mechanismassociated with the connecting circuit and having motor means and aplurality of contacts, a ringing signal connected to one contact of theswitching mechanism, a disconnecting signal connected to another contactthereof, a relay {controlled by uniting the connecting circuit with thecalled line for actuatingthe motor. means to close the contact to therim ing signal, and a supervisory relay therea er controlling the motormeans to close the to the disconnecting si al. A

In .testimonyfwhereo I have signed my name to this specification in thepresenceiof two subscribing witnesses, this l8th dayiol Qctober 1910..WILLI'AM .G. BLAUVEIJT. fW'itnessesg;

Pnnnr VVooLiicorr, WILBUR L. VAT'IIER.

